The full-field displacement intelligent measurement of retaining structures using UAV and 3D reconstruction

The displacement of retaining structures can provide an analytical basis for assessing its working condition. To address the shortcomings of conventional measurement techniques, which often involve high risk and labor-intensive procedures. This paper proposes an innovative approach. This method proposes the Improved-PatchmatchNet algorithm, Improved-ICP algorithm, and introduces the comparison algorithm M3C2 to achieve full-field displacement intelligent measurement of retaining structures. It is convenient, cost-effective, and acceptably accurate. In order to establish the practicality of this method, a physics-based graphic model (PBGM) is employed. During the PBGM model tests, it is observed that the error of the algorithm is less than 1 cm and the error of the average value is less than 6.82 %, which proved its effectiveness to measure the displacement of retaining structures. Ultimately, this method was employed to measure a framed composite anchored soil nail wall. Through six UAV flights over 18 months, five displacement measurements are obtained.